This site
suggests 'Japanese have a special ability to fall asleep anywhere at
anytime' & crowd doesn't make much of a difference to them.
And
if you are among those who are interested in learning new skills of
sleeping in impossible places & positions then this is the best site which has got a lot to offer.
And
even after all this, if one needs to sleep at work then there is a
solution to this too. Just close your eyes & stick the eyes
stickers & fall asleep & relax yourself. Just in case if you
are thinking otherwise, then perhaps you should stick to a cup of
coffee.